1. Field of the Invention
The present invention relates to a positioning structure of a handle, more particularly to a retractable handle having two sliding tubes can make the positioning of the retractable handle in a firmer manner.
2. Description of the Prior Art
A typical positioning structure of retractable handle is disclosed in Germany Pat. No. 20018889U1, and is shown in FIG. 5, which contains mutually sliding and connecting the inner tube (40) and the outer tube (41). On one end of the inner tube is a base (42) having an axial hole (43), a pillar shaped multilateral rotating rod (45) passing through the hole (43). Both sides of the base of the tube (40) are hollow spaces (44), and a movable piece (46) in each hollow space (44). There is a rotating ring (47) on the outer tube, and on one end of the rotating rod (45) is fixed on the rotating ring (47).
However, this conventional product will result in the following disadvantages caused by poor structure design. The device has the following two disadvantages:
1. Unstable fixing: conventional products applied the non-round shape eccentric protruding part on the rotating rod to rotate and push the movable piece, then pushing the base which is countered to the base to move outward then prop to the inner wall of the outer tube, thus fixed the inner and the outer tube. However, the movable piece, which counters to the eccentric protruding part, will generate contrary counterforce to the rotating rod. Though those conventional product came with springs, ball bearings as fixing structure, the fixing force from the ball bearings are not sufficient, therefore caused the movable piece to spontaneously move inward and be unable to fix between the inner and outer tubes.
2. Damaged easily: the conventional products applied the eccentric protruding part on the rotating rod to push the movable piece which will generate bigger attrition between the eccentric protruding part on the rotating rod and the inner wall of the movable piece. General rotating rods are made of metal, and movable pieces are made of plastic or soft materials, thus after continuous use, the inner wall of the movable piece will be worn and torn by the rotating rod and being ported and the internal diameter gets bigger, thus the rotating rod will be unable to push the movable piece outward and fix, so the sliding tube can no longer be used.